removeSlashPrefix

pathPatternToPerl5Regex

Converts UN*X style path to regular expression (originally, for Perl 5 dialect, but also works for Java's
dialect).
In additional to standard UN*X path meta characters (*,
?) it understands **, that is the same as
in Ant. It assumes that the paths what you will later match
with the pattern are always starting with slash (they are absoulte paths
to an imaginary base).